• A bull elk bugles in Yellowstone National Park

    Yellowstone

    National Park ID,MT,WY

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  • Craig Pass Closed for the Season; Mammoth to Norris Closed Sept. 14-30

    The road linking West Thumb and Old Faithful is closed for the season—traffic should detour through West Thumb, Lake, and Canyon. The road from Mammoth to Norris is closed for two weeks—traffic should detour over Dunraven Pass. More »

Hot Springs and How They Work

Emerald Spring glows green.

Emerald Spring

Hot springs with names like Morning Glory, Grand Prismatic, Abyss, Emerald, and Sapphire, glisten like jewels in a host of colors across the park's harsh volcanic plain. They are the most common hydrothermal features in the park.

Their plumbing has no constrictions. Superheated water cools as it reaches the surface, sinks, and is replaced by hotter water from below. This circulation, called convection, prevents water from reaching the temperature needed to set off an eruption. [View the anatomy of a hot spring.]

Did You Know?

Fire in Yellowstone Pineland in 1988

The 1988 fires affected 793,880 acres or 36 percent of the park. Five fires burned into the park that year from adjacent public lands. The largest, the North Fork Fire, started from a discarded cigarette. It burned more than 410,000 acres.